Create Your Own Canopy Map
There’s no magic number, especially when you consider the vast range of climate and soil variability across the country. But setting a goal is important; tree cover in US urban areas is declining at a rate of about 4 million trees a year. And virulent pests and disease could drive these numbers dramatically higher.
Many communities already have access to tree canopy maps from their own planning departments, from regional planning organizations or colleges and universities. It’s worth asking. And you may find what you’re looking for on one of the map collections like i-Tree’s extensive library of city reports or MIT’s TreePedia series that uses a unique metric called the GreenView Index.
Often your municipal or county planning office can provide a detailed canopy map. Or, if you have sufficient funds, you can find consultants [even some with drones] who can overfly your community and create a canopy map.
From there, you can find guidance on canopy assessment from the USDA Forest Service in this publication.
If you’re starting from scratch on a tight budget, i-Tree Canopy can help you do it yourself. This free tool uses embedded aerial imagery that allows you or trained volunteers to characterize land cover in your community. You choose the land use categories, and then pinpoint them on the map.In a few hours, you and your team can characterize 500+ randomly selected points and create a map that’s 95 percent accurate, when compared to ground-based inventories.